(1) Field of the Invention
The present invention relates to a digital photocopier which performs an electronic sorting function by storing image data into a memory.
(2) Description of the Related Art
The recent technology enables a general digital photocopier to perform a so-called electronic sorting function: copying sheets are sorted into sets by electronic technique instead of particular mechanism. In this electronic sorting, image data of all the documents are stored into a memory in the form of compressed code data which are read out at a time of the printing as many times as the number of copies. The image data are compressed into the code data because a capacity of the memory is relatively small for the massive amount thereof.
Yet, the amount of the compressed code data exceeds the capacity depending on the size, particulars, and the number of pages of the documents. For example, if ten pages of documents are to be copied when the memory has a capacity of five pages, the memory becomes full when it has stored the data up to the fifth page. When this "memory-full" happens, users decide whether to eliminate the stored data or to make the desired number of copies up to the pages of which data are safely stored in the memory and repeat the same procedure for the remaining documents.
However, eliminating the stored data means a waste of time. As well, repeating the procedure means to cause trouble; for the copy sheets per set are discharged onto a single catch tray and the sets are sorted out manually in this type of photocopier, the users must repeat this manual sorting as many times as the procedure is repeated.
Further, the memory can be programmed to make copies in any desired sequence of pages when the memory has stored the data of all documents. However, the sequence may be disordered once the memory-full happens. As a result, all the copy sheets must be checked and sorted out manually after all, which is troublesome all the more.